Fig. 2

ATP, Mg⁺⁺ titrations and time course of G-I repair in human nuclear extracts. Each reaction contained 90 μg HeLa extracts and 21 fmol G-I substrate. a Repair reactions with HeLa extracts were determined as described in Methods except that where indicated ATP was added. b Repair reaction with HeLa extracts were performed as described in Methods except where indicated Mg²⁺ was added. c Reactions were performed under standard conditions and scaled; 10-μl samples were removed as indicated. DNA products were digested with AlwNI and XhoI and then subjected to agarose gel electrophoresis to score for the repair of dI lesion. The bar pointing to the 7.2-kb fragment represents unrepaired substrate linearized with AlwNI; size marker (M) of 4.1 and 3.1-kb fragments are indicative of repaired products that were generated by treatment of M13LR1 with AlwNI and XhoI. d Quantitative analysis of the time course reaction, the error bars represent S.D. from three determinations